There are different definitions of deep peat, depending on the context in which it is being defined.
In forestry in Scotland, the definition of deep peat is 50 centimetres depth or more.
The origins of the 50 cm deep peat threshold in Scotland can be traced back to 1970 in the Soil Survey of Scotland.
Origins of the Soil Survey of Scotland 50 cm threshold to define a Peat soil (archived Scottish Government website)
The UK Forestry Standard shows that no new forests are to be established:
- on peat depths of 50 centimetres or more
- where it compromise the hydrology of adjacent bog habitats
The UK Forestry Standard's 5th edition included an expert review of the definition of deep peat.
UK Forestry Standard, 5th edition
The review concluded that:
- it was agreed the 50 cm deep peat threshold be retained
- there was no settled scientific evidence on carbon balance or tree growth rate to support lowering the threshold from 50 cm
- each UK nation can define their own thresholds if required
The UK nations will continue to support evidence gathering and any changes in evidence will be reflected.
